1. Field of the Invention
The present invention relates to a portable device having a touch input unit, and in particular, to a control method for providing a partial lock function in a portable device having a touch input unit according to types or touch input manners of the touch input unit to reduce malfunction and improve usability of the portable device.
2. Description of the Related Art
With the remarkable development of communication techniques and semiconductor techniques, a variety of new portable devices has been developed for convenient and comfortable use. The portable devices include mobile phones, Personal Digital Assistants (PDAS) and MP3 players.
Currently, an increasing number of portable devices use a touchpad, a touchscreen or an optical jog as input means. The input means include various types of hardware, but have a common feature in that an input function is performed by contact of a finger of a user. Thus, the input means are referred to as “a touch input device.”
The touch input device performs an input function by touch and sweep motions of a user's finger, compared with a typical button input unit operated by recognition of a push motion by a user's finger. Such a touch input manner determines even a light touch of the body or of another object to be an operation intention of a user and performs a touch input function. Thus, although the touch input manner may be regarded as an intuitional and convenient input manner, in practice it causes frequent malfunction.
In order to prevent malfunction, techniques using a lock function have been introduced. A conventional technique uses a lock key operated in the same manner as a button input unit to provide lock/unlock functions to a touch input unit. However, in the case that the touch input unit has at least two types of input means (for example, a touchpad and a touchscreen) or an input manner of touch and sweep, the conventional technique may result in an inconvenient lock function.
For example, in the case that a portable device having a touchpad and a touchscreen is put in a pocket or a bag, the touchpad may respond to static electricity, thereby causing malfunction of the portable device. In order to prevent this problem, a state of the entire device may be changed to a lock state, which makes it ineffective. When a communication device such as a mobile phone is in a lock state, the communication device may not rapidly and effectively respond to an emergency situation. Further, malfunction is sufficiently prevented only by lock of a touch manner, but the whole input manner may be locked, thereby causing inconvenience.
Another conventional technique reduces the sensitivity of a touch input unit in order not to respond to external shocks to some extent. However, such a technique reduces usability of a portable device.